It's not as dangerous as some other widow spiders because the Brown Widow Spider is less likely to bite someone, and has less toxic venom. Physical Description and Identification Adults.

Habits: Brown widow species have poisonous venom, though it is rarely fatal. There is a general striped pattern on the legs and dorsal (top) side, and brown mottling on the ventral (bottom) side.
Its coloration ranges, but it is usually either dark grey, brown, or black. Why is that? Female: about 12-16 mm (> 0.5 inch) long (body length only, not including legs) Male: much smaller, 6-8 mm (about half the body length of a female) but with longer legs. Also, brown widow bites are less painful than the bite of the western black widow. Female: about 12-16 mm (> 0.5 inch) long (body length only, not including legs) Male: much smaller, 6-8 mm (about half the body length of a female) but with longer legs. It is a venomous creature, and must be handled with respect. Characteristics: Black or dark brown. The population of this kind of spider continuously expands within Southern California and also northward towards Central California. How to identify (and misidentify) Brown Widow The brown widow spider, Latrodectus geometricus, is not native to the United States. Like black widow spiders, brown widows have an hourglass marking on the underside of the abdomen, but their hourglass is typically orange or yellow. Brown Widow Spiders usually curl up into a ball, and drop to the ground as a primary defense. There is a geometric pattern on the upper side of the abdomen. The brown widow is a medium to large spider that is slightly smaller than its cousin, the black widow. Theridiids are known as comb-footed spiders because of the comb-like rows of stout, curved bristles on the tarsi (feet) of the hind pair of legs ( Figure 1 ). The Brown Widow Spider is a great tropical spider to be kept in captivity. However, such general "common names" are of limited use as the diversity of species is much greater. How to identify (and misidentify) Brown Widow The brown widow spider, Latrodectus geometricus, is not native to the United States.


So the Brown Widow has great potential to harm, and should be handled very carefully if encountered. Brown widow spider is part of the local spider fauna in the California area of the USA most particularly in urban Los Angeles and San Diego area. The brown widow spider (Latrodectus geometricus Koch) belongs to the family Theridiidae (Foelix 2011, Howell and Jenkins 2004). Theridiids are known as comb-footed spiders because of the comb-like rows of stout, curved bristles on the tarsi (feet) of the hind pair of legs ( Figure 1 ). Even though brown widow populations have jumped, he said, they’re still being found mainly in urbanized areas. Figure from Ibister & Fan, 2011. Red widow (Latrodectus bishop) Adult female red widow spiders are reddish-orange, with reddish colored legs and a black or dark colored abdomen. The top of the abdomen usually has rows of red or orange spots outlined in white or yellow.